Authorizing local application activity using remotely defined security data

ABSTRACT

Systems and methods, including computer software adapted to perform certain operations, can be implemented for preventing content received from non-trusted sources from accessing protected data. A sequence of instructions and multiple permission indicators associated with the sequence of instructions are received. One or more of permission indicators are associated with a protected activity. An instruction within the sequence of instructions associated with the protected activity is identified. A determination is made whether execution of the identified instruction is permitted based, at least in part, on the one or more permission indicators, and the protected activity is performed if execution of the identified instruction is permitted.

BACKGROUND

The present disclosure relates to providing and enforcing securityprocedures in computer systems in general and more specifically relatesto providing and enforcing security procedures in mobile informationsystems. In a mobile information system, subscribers may register with awireless service provider to receive various types of content from theservice provider on their mobile devices. The subscriber's mobile devicemay include a resident interactive multimedia application environmentthat includes capabilities for displaying graphics, video, animation,audio, and the like. Examples of such interactive multimedia applicationenvironments are the different versions of the Adobe® Flash®-basedplatform. Content provided to mobile devices equipped with suchapplication environments is sometimes delivered in executable fileformats such as the precisely described SWF (small web format) binaryvector graphics format. SWF provides a compact, TAG-based, easilyextendible format that supports streaming, bitmap and vector graphics,and scripting.

SUMMARY

Computer systems, such as mobile information systems, may includesecurity mechanisms to prevent content received from non-trusted sourcesfrom accessing protected data. For example, a subscriber to a mobileinformation system may also subscribe to phone services from thewireless provider. Call logs, address books, and other data filesassociated with the phone services may be stored in a protected areainaccessible to content received from non-trusted sources. Such systemsmay also include security procedures to prevent content received fromnon-trusted sources from performing unauthorized activities. Forexample, a mobile device application executing a SWF file originatingfrom a particular network domain might allow the SWF file to interactonly with content originating from that particular network domain. Anyattempt by the SWF file to interact with content originating from adifferent network domain may be blocked.

This specification describes technologies relating to providing andenforcing security procedures in computer systems.

In general, one aspect of the subject matter described in thisspecification can be embodied in a method that includes receiving asequence of instructions and one or more permission indicator associatedwith the sequence of instructions. A first of the permission indicatorsis associated with a protected activity. An instruction within thesequence of instructions that is associated with the protected activityis identified. A determination is made whether execution of theidentified instruction is permitted based, at least in part, on thefirst permission indicator. The protected activity is performed ifexecution of the identified instruction is permitted. Other embodimentsof this aspect include corresponding systems, apparatus, and computerprogram products.

In another general aspect, a system includes a user interface device, apersistent storage device, and one or more processors operable tointeract with the user interface device and the persistent storagedevice. The one or more processors receive a transmission from a remotesource. The transmission includes a sequence of instructions and apermissions data structure associated with the sequence of instructions.The permissions data structure includes one or more permissionindicators associated with one or more protected activities. Thesequence of instructions and the permissions data structure are storedin the persistent storage device. The sequence of instructions and thepermissions data structure are retrieved from the persistent storagedevice in response to a stimulus received through the user interfacedevice. A determination that a first protected activity is prohibitedbased, at least in part, on the one or more permission indicators, andthe sequence of instructions are executed to block the first protectedactivity. Other embodiments of this aspect include correspondingmethods, apparatus, and computer program products.

These and other embodiments can optionally include one or more of thefollowing features. The sequence of instructions and the one or morepermission indicators are received in a single transmission. Thesequence of instructions and the one or more permission indicators arereceived by a mobile device. The received sequence of instructions andthe received at least one permission indicator are stored in apersistent storage device on the mobile device. An update to the one ormore permission indicators is received and stored in the persistentstorage device on the mobile device. The sequence of instructions andthe one or more permission indicators are received from a remote sourcein communication with the mobile device. The value of the firstpermission indicator is set at the remote source. The one or morepermission indicators include multiple permission bits, and the firstpermission indicator corresponds to a first of the permission bits. Asecond of the one or more permission indicators is associated with adifferent protected activity, and the second permission indicatorcorresponds to a second of the permission bits. The sequence ofinstructions is included in a SWF file. The permission indicators areassociated with an information source. When an updated value for thepermission indicator is received, the updated value for the permissionindicator replaces the permission indicator in the persistent storagedevice. Prior to identifying the instruction, a sequence of instructionsis received and stored in the persistent storage device. The permissionindicator and the sequence of instructions are stored at a location inthe persistent storage device associated with the information source.The permission indicator occupies one of multiple permission indicatorpositions within a permissions data structure, and the permissionindicator is assigned to the permission indicator position at the remotesource.

The one or more processors include a client operable to interact withthe remote source through a data communication network, and the remotesource is operable to interact with the client as a server. The numberof permission bits is greater than the number of permission indicators.

Particular embodiments of the subject matter described in thisspecification can be implemented to realize one or more of the followingadvantages. Permissions associated with protected activities in a mobileinformation system can be configured at a central remote location andpropagated to individual mobile devices for enforcement by preconfiguredsoftware on the mobile devices. Permissions associated with protectedactivities can be added, removed, or updated at the central location bya mobile service provider or other trusted third party. Individualmobile device subscribers need not be aware that updates have occurred.New content provided to individual mobile devices can be accompanied bypermissions restricting the activities of the content. Content fromtrusted providers can be accompanied by permissions allowing the contentto perform restricted activities. Different sets of permissions can beassociated with different content channels, allowing content fromtrusted sources greater access to restricted activities, whilerestricting content from non-trusted sources. Received permissions canbe stored on the mobile device and are therefore immediately available,even when the device is not in communication with the central location.Application extension developers can define and implementextension-specific permissions that are configured at the centrallocation and provided to the extensions on the mobile devices.Individual protected activities can be governed by individualpermissions.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,aspects, and advantages of the invention will become apparent from thedescription, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an example system for providing system security by associatingpermissions with content.

FIG. 2 is an example data structure for use in associating permissionswith content in a mobile information system.

FIG. 3 is a flowchart illustrating an example method for associatingpermissions with content in a mobile information system.

FIG. 4 is a flowchart illustrating an example method for providingcontent and associated permissions in a mobile information system.

FIG. 5 is a flowchart illustrating an example method for preventingunauthorized activities in a mobile information system.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

When a computer system, such as a mobile information system, isconfigured to receive content from a non-trusted source, the computersystem may implement security procedures to prevent the content fromaccessing protected data or from performing unauthorized activities. Ina mobile information system, subscribers may register with a wirelessservice provider to receive various types of content from the serviceprovider on their mobile devices. Third party content providers may alsoregister or contract with the wireless service provider to providevarious types of content to subscribers over a network, such as theInternet, via the service provider. The subscriber's mobile device mayinclude a resident interactive multimedia application environment thatincludes capabilities for displaying graphics, video, animation, audio,and the like. Examples of such interactive multimedia applicationenvironments are the different versions of the Adobe® Flash®-basedplatform. Content provided to mobile devices equipped with suchapplication environments are sometimes delivered in executable fileformats such as the precisely described SWF binary vector graphicsformat. SWF provides a compact, TAG-based, easily extendible format thatsupports streaming, bitmap and vector graphics, and scripting. Contentmay include other data or files, such as a feature film, an executablesoftware update, or a software extension.

In some implementations, wireless service providers deliver content tothe mobile devices of their subscribers in the form of informationchannels. Each information channel may originate with the wirelessservice provider or may originate with third party content providers.When a subscriber subscribes to a particular information channel, thewireless service provider delivers content associated with thatinformation channel to the subscriber's mobile device. The content maybe delivered as a channel feed to a file system (i.e., a feed store)located on the mobile device. The feed store may be logically dividedinto separate compartments or memory allocations with each channelassigned its own compartment on a static or dynamic basis. Periodically,the wireless service provider may deliver channel content updates to themobile device. The updates may be provided according to a predeterminedschedule, in response to a request from the mobile device, in responseto an availability of updates at the content provider, in response to anexpiration or consumption (e.g., viewing) of content previouslydelivered to the mobile device or in some other way. Because the channelcontent is stored locally on the mobile device and frequently updated,the subscriber is usually able to access the channel without having towait for channel content or content updates to be delivered over thenetwork. The channel content may be automatically delivered to themobile device in the background (i.e., without a specific user requestand/or while the mobile device is otherwise idle or being used to viewother channels or perform other operations.

For example, a wireless service provider may offer several differentinformation channels to its subscribers. Some information channels maybe freely available to all subscribers, while other information channelsmay require premium subscriber status. The content of some informationchannels may originate with the wireless service provider. The contentof other information channels may originate with third parties that haveregistered with the service provider. The content of still otherinformation channels may originate with other sources. The offeredinformation channels may include a premium news channel. If a subscriberhas subscribed to the premium news channel, then the wireless serviceprovider may establish a channel feed to periodically or sporadicallydeliver content from the premium news channel to the feed store locatedon the subscriber's mobile device. When the subscriber accesses thepremium news channel, processes on the mobile device retrieve thecontent from the feed store. Even if the subscriber rarely or even neveraccesses the premium news channel, the channel feed may provide forregular updates of channel content in the feed store based, for example,on an expiration of content and/or an availability of new content.

Channel content may be in the form of text, images, vector graphics,bitmaps, frame-based animation, video, or in any other format supportedby the mobile information system, and may include executable scripts orother sequences of instructions. Depending on the format of the channelcontent, an application running on the mobile device, such as a mediaplayer or other type of runtime component, may be invoked to run thescript, execute the instructions, or otherwise display the content. Oneexample of such a mobile information system is described in U.S. patentapplication Ser. No. 10/791,298, filed Mar. 1, 2004 and entitled “MOBILERICH MEDIA INFORMATION SYSTEMS,” the entire contents of which are herebyincorporated by reference.

To prevent channel content such as script files or other executablefiles from performing unauthorized activities, the mobile informationsystem may be configured to associate permissions with the informationchannel. For example, a wireless service provider administering themobile information system (e.g., T-Mobile®, Verizon Wireless®, or SprintNextel®), upon establishing a new information channel, may associate aset of permissions with the information channel. The mobile informationsystem may then communicate some or all of these permissions byincluding permission indicators in the channel feed established by thewireless service provider over a wireless network, either as part of thefeed for each channel, as part of a separate service maintenancechannel, or as overhead data separate from the channel feed. Processeson the mobile device may then review these permission indicators indetermining whether an information channel is allowed access torestricted activities and data.

FIG. 1 illustrates an example system 100 for providing system securityby associating permissions with content. System 100 represents a mobileinformation system for delivering mobile data services to mobile device110. The mobile information system represented in system 100 isadministered by a wireless service provider, such as T-Mobile®, VerizonWireless®, or Sprint Nextel®, that operates wireless network 106.Subscribers to the wireless service may receive external content fromcontent providers 118 through mobile device 110. In someimplementations, mobile device 110 is a mobile phone. In otherimplementations, mobile device 110 is a personal data assistant, alaptop computer, or any other device suitable to receive content overwireless network 106. Mobile device 110 may be configured to store localdata 112, which may include call log 130, contacts 132, and favorites134, as well as various other types of local data (e.g., settings andpreferences, calendar appointments and reminders, task lists, and thelike). Call log 130 may represent calls recently initiated or receivedby mobile device 110. Contacts 132 may represent a subscriber'sassociates and may include names, home and business addresses, phonenumbers, email addresses, and other information related to thesubscriber's associates. Favorites 134 may represent the phone numbersassociated with the subscriber's calling plan. Call log 130, contacts132, and favorites 134 represent examples of data that may be stored aslocal data 112 on mobile device 110. Individual implementations mayinclude none, some, or all of these examples, in addition to other typesof local data not shown.

At a high level, server system 104 may retrieve information from contentproviders 118, organize the retrieved information along with some or allof any associated permissions 140 into individual information channelfeeds, and deliver the information channel feeds to client 102. Client102 may then store the information channel feeds, including theassociated permissions, in feed store 114. In addition to the dynamicchannel feeds received from server system 104, feed store 114 may alsocontain one or more static feeds 156. Static feed content and associatedpermissions may be preloaded on mobile device 110 instead of deliveredby server system 104. In addition to providing information, channelfeeds may also be used to provide services, such as a home page userinterface, calendar user interface and services, or other userinterfaces or specialized application services. From a securitystandpoint, there may be little or no difference between static feedsand dynamic feeds or between information channels and service channels.

When a subscriber attempts to access a particular information channel,for example, channel B 150, client 102 may retrieve channel B content154 and channel B permissions 152 from feed store 114. Depending on theformat of channel B content 154, client 102 may provide channel Bcontent 154 to runtime component 116. In some implementations, channel Bcontent 154 is a SWF file and runtime component 116 is an Adobe®Flash®-based runtime component. If channel B content 154 attempts toaccess restricted data or attempts to perform a protected activity,client 102 may check channel B permissions 152 to determine whether toallow the attempted data access or protected activity. Client 102 andruntime component 116 may form two parts of a single application 108running on mobile device 110. The application 108 may include a virtualmachine running on a device platform 128.

In some implementations, the functionality of runtime component 116 maybe extended. Such an extension 160 may be used to expand thefunctionality of runtime component 116, such as by providing support foradditional commands. For example, a service provider may wish to providechannel content that displays or otherwise accesses or manipulates datafrom local data 112 such as call log 130. The service provider maydevelop a custom command or instruction that can be provided in thechannel feed and stored in feed store 114. Such a command may beunrecognized by unextended runtime component 116. The service providermay then install a custom extension 160 on mobile device 110 thatrecognizes and performs the custom command or instruction, effectivelyincreasing the number of commands or instructions recognized by runtimecomponent 116. In another example, a third party content provider maydevelop a custom command or instruction to perform some other activity.Extension 160 may be distributed preinstalled on mobile device 110 ormay be downloaded to mobile device 110, for example over wirelessnetwork 106.

Client 102 provides a framework for displaying and managing contentreceived on mobile device 110, including content received from serversystem 104. Client 102 may be responsible for the caching and renderingof received content, for communication with server system 104, and forvarious other tasks. Client 102 may manage subscriber input and memorydevices 112 and 114. In addition, client 102 may manage securityfeatures that protect the privacy of subscribers and content and preventunauthorized parties from interfering with the service. In someimplementations, client 102 is distributed preinstalled on mobile device110, while in other implementations, client 102 or an update to client102 is downloaded to mobile device 110, for example over wirelessnetwork 106.

Client 102 may access runtime component 116 to render a user interfaceand content. In some implementations, runtime component 116 is a mediaplayer that supports vector graphics, bitmaps, and frame-basedanimation, as well as text input and dynamic text. Runtime component 116may be able to process files, such as SWF files, in which contentproviders 118 use native device fonts or embed arbitrary fonts. Runtimecomponent 116 may also support scripting integration with mobile device110 capabilities, including keypad navigation, button presses,notification, messaging, and media playback, as well as integration withgeneral mobile device 110 operating system functionality. This enablesclient 102 to be integrated with other mobile device 110 applicationsand functionalities. Scripting may be accomplished with ActionScript™ orany other suitable scripting language supported by runtime component116.

Client 102 may be configured to interact with mobile device 110'sunderlying features and applications through a set of scriptablecommands. Such commands may enable channel content to retrieve and setsubscriber preferences, provide time and date information from the hostenvironment, or launch external applications such as a browser or mediaplayer. In some implementations, upon launching an external application,the subscriber is instantly transferred to that application. Client 102may maintain the state of the user interface so that the subscriber canreturn to the same screen of client 102 from which the externalapplication was launched, creating a perception of an integratedexperience.

Client 102 may have a fully customizable user interface design thatconsists of individual Flash® elements (i.e., SWF files) independent ofclient 102's core functionality. In some implementations, the SWF filesenable subscribers to use mobile device 110's soft keys to controlnavigation and client 102's meta functions such as setting preferences.Client 102 may be updated over wireless network 106 and may use anasynchronous communication protocol that updates all content through abackground delivery mechanism that is transparent to subscribers. Thisenables subscribers to continue browsing one information channel, forexample, channel B 150, while a different information channel is updatedin the background. Subscribers can also change their preferences whenoffline; the transaction-based client-server protocol may ensure thatsuch requests will be fulfilled the next time client 102 connects toserver system 104. Communications between client 102 and server system104 may be facilitated through libraries native to platform 128.Platform 128 represents the device-dependent operating system running onmobile device 110. Example implementations of platform 128 are BREW® OS,Symbian OS™, BlackBerry® OS, Windows Mobile® OS, Palm OS®, Linux,Windows XP®, Mac OS®, and the like.

When running in background mode, client 102 may minimize battery usagewhile periodically receiving updates from server system 104. In someimplementations, subscribers can choose between a number ofbattery-conserving update options, for example, always update, updateonly when battery strength is above a certain level, and never update.If supported by platform 128, different applications may be runningsimultaneously. In such cases, client 102 may minimize its use of memoryresources when other applications are active. For example, client 102may have a hibernate mode in which it consumes only a fraction of itsnormal operating memory. Client 102 may also be configured to limit thenumber of information channels to which a subscriber may subscribe. Whenthis limit is reached, client 102 may require a subscriber to remove aninformation channel before a new information channel may be added.Client 102 may also support Short Message Service (SMS) signaling,allowing server system 104 to awaken client 102 and initiate animmediate content update in the case of important events such asbreaking news or an immediate retraction of inappropriate content.

Server system 104 may include clusters of feed servers 122 and datasource servers 120, as well as report server 126. Report server 126 mayallow service providers to monitor server activities and network trafficand may be integrated with other enterprise reporting solutions. Theclient-server architecture of system 100 may use clustering technologyto help ensure performance, reliability, and scalability whileminimizing deployment complexities through a flexible integrationframework. Server system 104 may aggregate content from external contentproviders 118 received over the Internet 170 and organize the contentinto channel content feeds. Server system 104 may filter content feedsbased on user preferences, mobile device 110 types, and access controls.Server system 104 may deliver the content feeds to client 102 overwireless network 106. Data source servers 120 may retrieve, normalize,and aggregate content from the web servers of content providers 118, maytransform various formats of retrieved content, for example, into acommon XML format, and may pass the content on to feed servers 122 fordelivery to client 102. Retrievals may be scheduled at predeterminedintervals, at which times only differential updates may be collected.Data source servers 120 may be configured to handle content feeds invarious formats (e.g., RSS, Atom, XML, etc.). Content feeds may supportembedded content types including, for example, text, images, and SWFfiles.

Using system 100, service providers may be able to provide targeted dataservice offerings to subscribers. Service providers may be able topromote specific content bundles to certain segments such as businesspeople, teens, casual users, and others. Service providers may be ableto make specific content bundles available to all subscribers in, forexample, a channel guide, allowing subscribers to select specificcontent bundles. To increase network efficiency, server system 104 mayoperate in an occasionally connected data model and may use acommunication protocol that enables differential updates, minimizingunnecessary exchanges of data between server system 104 and client 102.For example, in the case of a weather channel, only an update to thetemperature may be required, while all other content, such as images,video, or forecasts, remains the same.

Server system 104 may be equipped with an administrator process 124providing the functionality required to manage the servers, includingchannel administration, subscriber administration, and systemmanagement. Using administrator process 124, service providers cancheck, for example, the amount of network traffic each channelgenerates, deactivate poorly performing channels, and dynamicallyprovision, modify, or remove channels, among other tasks. As part ofchannel administration, service providers may use administrator process124 to configure and store permissions 140 and associate permissions 140with individual channel feeds. At least because the content in anindividual channel feed may originate from more than one network domain,or even more than one content provider, security based strictly ondomain of origin alone may be insufficient. Permissions allow theservice provider to define with particularity the types of protectedactivities available to a channel. A set of permissions may bemaintained on server system 104 for each channel supported by the mobileinformation system, and may be delivered via the channel content feed toclient 102 from server system 104. In some implementations, thepermissions associated with a channel are delivered to client 102 withthe initial delivery of content for the particular channel, andthereafter delivered only if the channel's associated permissions havechanged. In other implementations, the permissions or a subset of thepermissions associated with a channel are delivered to client 102 witheach delivery of content for the particular channel. In still otherimplementations, a different scheme for delivering permissions may beemployed, so long as permissions received by client 102 are associatedwith at least one channel.

When client 102 receives a content update from server system 104 via thechannel feed, client 102 stores both the channel content and thepermissions associated with the content in feed store 114. For example,when client 102 receives a content update for Channel B, client 102updates Channel B feed 150 in feed store 114. Both Channel B content 154and the associated Channel B permissions 152 are stored. Channel B feed150 may be updated multiple times before a subscriber ever accesses it.When a subscriber accesses Channel B through the mobile device 110 userinterface, client 102 may retrieve Channel B content 154 (e.g., a SWFfile) and Channel B permissions 152 (e.g., a set of permissionindicators) and provide at least the content to runtime component 116(e.g., a media player). Typically, the client 102 may retain thepermissions 152. This allows the client 102 to enforce a degree ofsecurity by determining whether actions requested by the content areallowed. In some implementations, runtime component 116 may receiveChannel B permissions 152. Runtime component 116 may make no attempt tointerpret or otherwise process Channel B permissions 152 but simplyretains them as associated with Channel B content 154. As runtimecomponent 116 executes Channel B content 154, any attempt by Channel Bcontent 154 (or runtime component 116) to perform a protected orrestricted activity may pass through client 102 and cause client 102 toretrieve or access the relevant permissions 152 (e.g., from the client'sown internal memory or cache) along with the relevant data associatedwith the protected or restricted activity. Client 102 may then inspectChannel B permissions 152 to determine whether the attempted activity isallowed for Channel B. If the attempted activity is not allowed, client102 may prevent the execution of the attempted activity.

As runtime component 116 executes Channel B content 154, any attempt byChannel B content 154 to access custom extension 160 may cause customextension 160 to retrieve one or more Channel B permissions 152 fromclient 102. In this case, neither runtime component 116 nor client 102may attempt to interpret or otherwise process Channel B permissions 152.Custom extension 160 may inspect Channel B permissions 152 to determinewhether any permissions dedicated to custom extension 160 have beendefined and if so, custom extension 160 is responsible for interpretingsuch dedicated permissions and for taking appropriate action.

In some implementations, client 102 can operate in more than one mode,for example, a server-managed mode and a non-server-managed mode. In anon-server-managed mode, client 102 may receive 172 content that is notmanaged by server system 104, for example from external server 174 overInternet 170. Unmanaged content may not be stored in feed store 114.Permissions associated with unmanaged content may still be provided toclient 102; however, the permissions may be read from a configurationfile delivered to client 102 in a loader application rather than readfrom feed store 114. The loader application may deliver both the contentand the permissions associated with the content. In server-managed mode,permissions are provided by server system 104 as described above, andclient 102 will ignore any permissions provided by a loader application.

In server-managed mode, the channel activation process on mobile device110 begins with client 102 loading a file from feed store 114 intoruntime component 116. This file may be referred to as a root SWF. Aroot SWF is typically allowed to access content from its own channelfeed without permission. However, if a root SWF attempts to accesscontent from a different feed, a cross feed access permission may berequired. A cross feed access permission is one example of a permissionthat may be associated with a particular channel. A SWF with permissionto load items from another feed may not necessarily have permission toscript SWFs from that feed. A SWF attempting to access variables orfunctions inside of a second SWF is said to be scripting the second SWF.In some implementations, a separate permission governs whether a SWFfrom a channel feed may be scripted, and a SWF with permission to loaditems from a particular feed may script SWFs from that feed only if SWFsfrom that feed have permission to be scripted. Separate permissions maygovern whether a SWF is allowed to perform other activities, forexample, to load video files.

A root SWF may attempt to load a child SWF. If the child SWF is loadedfrom the same feed as the root SWF, the child SWF will typically inheritthe permissions of the root SWF. If the child SWF is loaded from anyother location, additional permissions associated with the root SWF maydetermine what its remote child SWF is allowed to do. For example, apermission may determine whether a remote child SWF is allowed to accessfeed store 114, and another permission may determine whether a remotechild SWF is allowed to inherit permissions from its parent SWF.

A root or child SWF may attempt to perform various activities using theActionScript™ getURL global function. Such activities may includereplacing the root SWF, loading a document into a browser, or sending anSMS or Multimedia Message Service (MMS) message, to name a few. In someimplementations, these and other getURL requests are each associatedwith a separate permission. For example, a root SWF may not require apermission to replace itself, but a child SWF may require a permissionto replace the root SWF. An HTTP/HTTPS call may require a permission,and an HTTP/HTTPS call with a post data request may require anadditional, separate permission.

The above examples represent only a few of the many circumstances wherecontent-associated permissions may provide dynamic, flexible, and fullycustomizable system security. A data structure useful in flexiblyassociating permissions with content is illustrated in FIG. 2. Exampledata structure 200 comprises three 32-bit substructures, with each bitin each substructure corresponding to a protected activity governed by apermission. Logic interpreting the permission bits may be designed toallow the protected activity when the bit is set, and to deny theprotected activity when the bit is not set. Alternatively, logicinterpreting the permission bits may be designed to deny the protectedactivity when the bit is set, and to allow the protected activity whenthe bit is not set. A separate set of permissions corresponding to datastructure 200 may be established for each channel supported by thesystem. In some implementations, arrays of 32-bit values may be used toprovide the flexibility to support greater numbers of permissions and/ormore permission data. Permissions may be passed from a loaderapplication at the server to the client as comma-delimited lists ofstrings, which facilitates adding new permissions and/or originalequipment manufacturer (OEM) or other third party permissions at a latertime without having to make changes to the application programminginterface (API).

A wireless service provider administering the mobile information systemmay use the administrator process on the server system to create a setof permissions according to data structure 200 for each channelsupported by the mobile information system. The service provideradministrator may determine, for every permission represented by apermission bit in data structure 200, whether the correspondingprotected activity is allowed or denied for the corresponding channel.These permission bits may be persistently stored on the server system,periodically updated by the service provider administrator, and providedto the client in the channel feed of each channel. When received at theclient, the permissions bits are persistently stored in the feed storealong with the channel content and retrieved by the client inconjunction with displaying or otherwise executing the channel contenton the mobile device. In some implementations, different permissions maybe associated with different types or sources of content within a singlechannel. Moreover, permissions may be associated with certain types orsources of content without regard to a particular channel.

In example data structure 200, the permission bits in substructure 210represent the standard permissions that govern protected activities thatare not associated with an extension to the runtime component. Suchstandard protected activities may include, for example, accessing localdata, accessing other feeds, cross-feed scripting, accessing the feedstore by a child SWF, performing a getURL command, replacing the rootSWF, inheriting permissions, and loading video. The standard permissionsare typically predefined in the architecture of the mobile informationsystem, and may be configured with default settings denying access toprotected activities. The wireless service provider administrator maythen selectively modify the standard permissions for particularchannels, while leaving other channels with the default permissionsettings. In example data structure 200, all bits in substructure 210have been defined; however, in some implementations, some bits will bereserved for future expansion.

The permission bits in substructure 230 represent custom extensionpermissions that govern protected activities associated with anextension to the runtime component. Such extensions may be provided bythe wireless service provider or by a third party (e.g., a partyauthorized by the wireless service provider to define at least somepermissions). These permission bits are originally reserved in thearchitecture of the mobile information system and are meaningless untildefined by the service provider administrator. For example, Extension Amay provide functionality that includes one activity that should beprotected, Extension B may provide functionality that includes fouractivities that should be protected, and Extension C may providefunctionality that includes two activities that should be protected. Thedeveloper of Extension A must coordinate with the service provideradministrator to reserve one bit in substructure 230 for use byExtension A, the developer of Extension B must coordinate with theservice provider administrator to reserve four bits in substructure 230for use by Extension B, and the developer of Extension C must coordinatewith the service provider administrator to reserve two bits insubstructure 230 for use by Extension C. The administrator process ofthe server system may provide the service provider administrator withthe necessary tools for defining the names and locations of the customextension bits, for setting default values for the custom extensionbits, and for modifying the custom extension bits. When these permissionbits are retrieved by the client from the feed store in conjunction withdisplaying channel content on the mobile device, the bits are simplyprovided to the custom extensions for interpretation and appropriateaction.

The permission bits in substructure 220 represent standard extensionpermissions that govern protected activities associated with anextension to the runtime component. Such extensions are typicallyprovided by the wireless service provider. Standard extensionpermissions are similar to custom extension permissions; however,standard extension permissions govern protected activities commonlyimplemented by service providers in mobile information systems, such asactivities associated with contact information or a call log. Standardextension permissions are predefined for the convenience of the serviceprovider. The service provider may choose whether or not to use thepredefined standard extension permissions when developing extensions.

Data structure 200 and its accompanying description illustrate oneexample for organizing content-associated permissions in a mobileinformation system. It will be understood that this data structure isfor illustration purposes only and that other data structures may beused so long as the data structure remains appropriate for communicatingpermissions from the server system to the mobile device client.

FIG. 3 is a flowchart illustrating an example method 300 for associatingpermissions with content in a mobile information system. At step 305, aservice provider administrator may determine whether a new contentprovider has registered to provide channel content to the mobile devicesof subscribers in the mobile information system. Alternatively, theservice provider administrator may determine whether a new channel isbeing established from an existing content provider or from some othersource. Because the channel content may include executable scripts orother sequences of instructions, and because that content may bedelivered to one or more mobile devices for execution, the serviceprovider may provide security features to ensure that content deliveredto the mobile device is unable to access protected data and/or unable toperform protected activities on the mobile device. Such securityfeatures may include associating a set of permissions with the channelfeed, communicating these permissions to the mobile device along withthe content in the channel feed, and reviewing these permissions at themobile device to determine whether an information channel is allowedaccess to restricted activities and data. As described above, thepermissions may include standard permissions, standard extensionpermissions, and custom extension permissions. The permissions may beenforced, for example, by the client 102, runtime component 116,application 108, and/or platform 128 (see FIG. 1), the operations ofwhich may be controlled, at least in part, by the wireless serviceprovider.

If the service provider administrator determines at step 305 that a newchannel feed is being established, the service provider administratormay set the standard permissions at step 310, the standard extensionpermissions at step 315, and any defined custom extension permissions atstep 320 for the new channel feed. The service provider administratorsets the standard permissions at step 310 by determining, for eachpermission in the set of standard permissions, whether the content inthe new channel feed is allowed to perform the activity governed by thepermission. For example, if the new channel feed will supply contentthat is strictly under the control of the service provider, local dataaccess may be allowed. But if the new channel feed will supply contentfrom a third party, local data access may be denied. Similarly, theservice provider administrator sets the standard extension permissionsat step 315 by determining, for each permission in the set of standardextension permissions, whether the content in the new channel feed isallowed to perform the activity governed by the permission. If customextension permissions have been defined for the mobile informationsystem, the service provider administrator sets the custom extensionpermissions at step 320 by determining, for each permission in the setof custom extension permissions, whether the content in the new channelfeed is allowed to perform the activity governed by the permission.

Some or all of the individual permissions may be preconfigured with adefault value. For standard permissions and standard extensionpermissions, these default values may be hard-coded in the administratorprocess or in another application associated with the server system.Default values associated with standard permissions and standardextension permissions may also be modified by the service provideradministrator. For custom extension permissions, the service provideradministrator may assign default values when defining the customextension permissions. When permissions are preconfigured with a defaultvalue, the service provider administrator may accept the default valuesfor some permissions while affirmatively setting the value of otherpermissions in steps 310, 315, and 320.

At step 325, the service provider administrator may determine whether anew custom extension permission is needed. If the new channel feed isconfigured to provide content that will execute in a custom extension,the developer of the custom extension may require one or more newpermissions for interpretation by the custom extension. The serviceprovider administrator defines the new custom extension permissions atstep 330 and sets the new custom extension permissions at step 335. Indefining a new custom extension permission, the administrator may selecta previously undefined permission reserved in the custom extensionpermissions data structure and assign it to the custom extension.

If the service provider administrator determines at step 305 that a newchannel feed is not being established, the service provideradministrator may determine at step 345 whether an update to thepermissions of an existing channel feed is needed. An update may beneeded, for example, if new content will be provided in an existingchannel feed requiring access to restricted data or activities or if newcontent will be provided in an existing channel feed for execution in acustom extension. If a permissions update is needed, the serviceprovider administrator may determine at step 350 whether the neededupdate is for existing permissions. Existing permissions includestandard permissions and standard extension permissions, as well ascustom extension permissions previously assigned to a particular customextension. If an update to existing permissions is needed, the serviceprovider administrator may perform the necessary updates at step 355 andthen may return to step 325 to determine whether a new custom extensionpermission is needed to complete the permissions update. A new customextension permission may be needed, for example, if new content will beprovided in an existing channel feed for execution in a customextension. The path for a new channel feed and the path for an update toan existing channel feed converge at step 340, where the new or updatedpermissions are persistently stored on the server system, where they maybe retrieved for future delivery in a content feed.

FIG. 4 is a flowchart illustrating an example method 400 for providingcontent and associated remotely defined permissions to a mobile devicein a mobile information system. As previously described, a server systemassociated with the mobile information system may communicateinformation in the form of information channel feeds to clientcomponents on mobile devices. Content delivered to the mobile devices inthe channel feeds may originate with the mobile information systemservice provider or with third party content providers. At step 410,processes on the server system may determine whether the content orpermissions associated with a channel have been updated. If so,processes on the server system may retrieve the channel's permissionsfrom persistent storage at step 420, and prepare a channel feedcontaining the permissions and the updated channel content at step 430.In some implementations, only a content update will trigger steps 420and 430 and a permissions update will be delivered in the channel feedalong with the next content update. In some implementations, permissionsare delivered with the first delivery of channel content to a mobiledevice and are only delivered in subsequent channel feeds when thepermissions have been modified.

After the channel feed is prepared, the server system may determine atstep 440 whether a channel subscriber's mobile device is acceptingchannel updates. A mobile device may not be accepting channel updates,for example, because it is powered off, because it is hibernating toconserve battery life, because it is configured to accept updates atanother time, because it is busy performing other tasks, or for otherreasons. If the device is accepting channel updates, then the serversystem may deliver the channel content and/or permissions to the deviceat step 450 and return to step 410 to wait for additional updates. Ifthe device is not accepting channel updates, then the server system maydetermine at step 460 whether the channel has been updated again. Ifnot, then the server system may return at step 440 to enter a loopwaiting to either deliver the channel feed to the device or to determinethat the channel has been updated again. If the channel content isupdated again before the previous update is delivered to the mobiledevice, a new feed may be prepared containing the additional updates.Method 400 may be performed for each channel supported by the mobileinformation system.

FIG. 5 is a flowchart illustrating an example method 500 for blockingunauthorized activities in a mobile information system. As previouslydescribed, a server system associated with the mobile information systemmay communicate information in the form of information channel feeds toclient components on mobile devices. At step 505, the client componentmay determine whether the server system has a channel feed ready todeliver to the mobile device. If so, the client receives the channelfeed, which may include channel content and the permissions associatedwith the channel content, at step 510. At step 515, the client may storethe received content and associated permissions in a feed store on themobile device. The mobile device feed store may provide separate storagefor the content and associated permissions for each channel subscribedto by the mobile device.

After the incoming channel feed is stored, or if the server has nochannel feed ready to deliver, the client may determine at step 520whether a subscriber is attempting to access a channel on the mobiledevice. For example, the subscriber may have navigated to a particularchannel through the device's user interface and pressed a button,touched a screen, or otherwise indicated that the channel should bedisplayed or otherwise invoked. If a subscriber is not attempting toaccess a channel on the mobile device, the client may return at step 505to wait for either an incoming channel feed or a channel access.

If a subscriber is attempting to access a channel on the mobile device,then the client may access the feed store at step 525, retrieve thechannel content and associated permissions, and provide the channelcontent to a runtime component, such as a media player, on the mobiledevice. The channel content may comprise a sequence of executableinstructions or commands. The runtime component may then identify aninstruction or command at step 530 and determine at step 535 whether theinstruction or command is implemented in an extension expanding thefunctionality of the runtime component. If so, the runtime component mayprovide the instruction or command to the custom extension (e.g., viathe client), and the client may provide the extension permissions, whichmay include standard extension permissions and custom extensionpermissions, to the custom extension and the custom extension, at step555, may review the extension permissions. If the instruction or commandis not implemented in a custom extension, the runtime component mayprovide the instruction or command to the client and the client, at step540, may review the standard permissions. If the permissions reviewindicates that an activity associated with the instruction or command isprohibited at step 545, then that activity is blocked at step 550. Ifthe permissions inspection indicates that an activity associated withthe instruction or command is not prohibited at step 545, then thatactivity is performed at step 560. The runtime component may thendetermine at step 565 whether additional commands or instructions areprovided in the channel content and if so, may return at step 530 toidentify another instruction. If no further commands or instructions areprovided in the channel content, the client may return at step 505 towait for either an incoming channel feed or a channel access.

The preceding flowcharts and accompanying descriptions illustrateexample methods. It will be understood that these methods are forillustration purposes only and that the described or similar techniquesmay be performed at any appropriate time, including concurrently,individually, or in combination. In addition, many of the steps in theseflowcharts may take place simultaneously and/or in different orders thanas shown. Moreover, methods may be used with additional steps, fewersteps, and/or different steps, so long as the methods remainappropriate.

Embodiments of the subject matter and the functional operationsdescribed in this specification can be implemented in digital electroniccircuitry, or in computer software, firmware, or hardware, including thestructures disclosed in this specification and their structuralequivalents, or in combinations of one or more of them. Embodiments ofthe subject matter described in this specification can be implemented asone or more computer program products, i.e., one or more modules ofcomputer program instructions encoded on a computer-readable medium forexecution by, or to control the operation of, data processing apparatus.The computer-readable medium can be a machine-readable storage device, amachine-readable storage substrate, a memory device, a composition ofmatter effecting a machine-readable propagated signal, or a combinationof one or more of them. The term “data processing apparatus” encompassesall apparatus, devices, and machines for processing data, including byway of example a programmable processor, a computer, or multipleprocessors or computers. The apparatus can include, in addition tohardware, code that creates an execution environment for the computerprogram in question, e.g., code that constitutes processor firmware, aprotocol stack, a database management system, an operating system, or acombination of one or more of them. A propagated signal is anartificially generated signal, e.g., a machine-generated electrical,optical, or electromagnetic signal, that is generated to encodeinformation for transmission to suitable receiver apparatus.

A computer program (also known as a program, software, softwareapplication, script, or code) can be written in any form of programminglanguage, including compiled or interpreted languages, and it can bedeployed in any form, including as a stand-alone program or as a module,component, subroutine, or other unit suitable for use in a computingenvironment. A computer program does not necessarily correspond to afile in a file system. A program can be stored in a portion of a filethat holds other programs or data (e.g., one or more scripts stored in amarkup language document), in a single file dedicated to the program inquestion, or in multiple coordinated files (e.g., files that store oneor more modules, sub-programs, or portions of code). A computer programcan be deployed to be executed on one computer or on multiple computersthat are located at one site or distributed across multiple sites andinterconnected by a communication network.

The processes and logic flows described in this specification can beperformed by one or more programmable processors executing one or morecomputer programs to perform functions by operating on input data andgenerating output. The processes and logic flows can also be performedby, and apparatus can also be implemented as, special purpose logiccircuitry, e.g., an FPGA (field programmable gate array) or an ASIC(application-specific integrated circuit).

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors, andany one or more processors of any kind of digital computer. Generally, aprocessor will receive instructions and data from a read-only memory ora random access memory or both. The essential elements of a computer area processor for performing instructions and one or more memory devicesfor storing instructions and data. Generally, a computer will alsoinclude, or be operatively coupled to receive data from or transfer datato, or both, one or more mass storage devices for storing data, e.g.,magnetic, magneto-optical disks, or optical disks. However, a computerneed not have such devices. Moreover, a computer can be embedded inanother device, e.g., a mobile telephone, a personal digital assistant(PDA), a mobile audio player, a Global Positioning System (GPS)receiver, to name just a few. Computer-readable media suitable forstoring computer program instructions and data include all forms ofnon-volatile memory, media and memory devices, including by way ofexample semiconductor memory devices, e.g., EPROM, EEPROM, and flashmemory devices; magnetic disks, e.g., internal hard disks or removabledisks; magneto-optical disks; and CD-ROM and DVD-ROM disks. Theprocessor and the memory can be supplemented by, or incorporated in,special purpose logic circuitry.

To provide for interaction with a user, embodiments of the subjectmatter described in this specification can be implemented on a computerhaving a display device, e.g., a CRT (cathode ray tube) or LCD (liquidcrystal display) monitor, for displaying information to the user and akeyboard and a pointing device, e.g., a mouse or a trackball, by whichthe user can provide input to the computer. Other kinds of devices canbe used to provide for interaction with a user as well; for example,feedback provided to the user can be any form of sensory feedback, e.g.,visual feedback, auditory feedback, or tactile feedback; and input fromthe user can be received in any form, including acoustic, speech, ortactile input.

Embodiments of the subject matter described in this specification can beimplemented in a computing system that includes a back-end component,e.g., as a data server, or that includes a middleware component, e.g.,an application server, or that includes a front-end component, e.g., aclient computer having a graphical user interface or a Web browserthrough which a user can interact with an implementation of the subjectmatter described is this specification, or any combination of one ormore such back-end, middleware, or front-end components. The componentsof the system can be interconnected by any form or medium of digitaldata communication, e.g., a communication network. Examples ofcommunication networks include a local area network (“LAN”) and a widearea network (“WAN”), e.g., the Internet.

The computing system can include clients and servers. A client andserver are generally remote from each other and typically interactthrough a communication network. The relationship of client and serverarises by virtue of computer programs running on the respectivecomputers and having a client-server relationship to each other.

While this specification contains many specifics, these should not beconstrued as limitations on the scope of the invention or of what may beclaimed, but rather as descriptions of features specific to particularembodiments of the invention. Certain features that are described inthis specification in the context of separate embodiments can also beimplemented in combination in a single embodiment. Conversely, variousfeatures that are described in the context of a single embodiment canalso be implemented in multiple embodiments separately or in anysuitable subcombination. Moreover, although features may be describedabove as acting in certain combinations and even initially claimed assuch, one or more features from a claimed combination can in some casesbe excised from the combination, and the claimed combination may bedirected to a subcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. In certain circumstances, multitasking and parallel processingmay be advantageous. Moreover, the separation of various systemcomponents in the embodiments described above should not be understoodas requiring such separation in all embodiments, and it should beunderstood that the described program components and systems cangenerally be integrated together in a single software product orpackaged into multiple software products.

Thus, particular embodiments of the invention have been described. Otherembodiments are within the scope of the following claims. For example,the actions recited in the claims can be performed in a different orderand still achieve desirable results. The described techniques may beimplemented in non-mobile environments (e.g., using wire-linecommunications, such as a cable connection, with a non-mobile client,such as a set-top box).

What is claimed is:
 1. A method comprising: receiving, from a server, asequence of instructions executable by a virtual machine on anelectronic device and at least one permission indicator associated withthe sequence of instructions, a first of the at least one permissionindicators associated with a protected activity on the electronicdevice, wherein the sequence of instructions, when executed by thevirtual machine, are adapted to present, through a user interface of theelectronic device, content associated with a particular informationchannel of a plurality of interactive information channels defined onthe electronic device in response to a selection of the particularinformation channel through the user interface; storing the sequence ofinstructions and the associated at least one permission indicator in aparticular segment of a feed store of the electronic device, wherein thefeed store includes a plurality of segments, with each segmentcorresponding to one of the plurality of information channels and theparticular segment corresponds to the particular information channel;receiving a request, through the user interface, to display the contentassociated with the particular information channel; retrieving thesequence of instructions from the particular segment of the feed storein response to the request; executing the sequence of instructions usingthe virtual machine; identifying, using the virtual machine, aninstruction within the sequence of instructions as being associated withthe protected activity; determining, using the virtual machine, whetherexecution of the identified instruction is permitted based, at least inpart, on the first permission indicator; and performing the protectedactivity if execution of the identified instruction is permitted.
 2. Themethod of claim 1, wherein the sequence of instructions and the at leastone permission indicator are received in a single transmission.
 3. Themethod of claim 1, wherein the electronic device comprises a mobiledevice and the sequence of instructions and the at least one permissionindicator are received by the mobile device, the method furthercomprising: storing, in a persistent storage device on the mobiledevice, the received sequence of instructions and the received at leastone permission indicator.
 4. The method of claim 3, further comprising:receiving an update to the at least one permission indicator; andstoring, in the persistent storage device on the mobile device, thereceived update to the at least one permission indicator.
 5. The methodof claim 3, wherein the sequence of instructions and the at least onepermission indicator are received from a remote source in communicationwith the mobile device.
 6. The method of claim 5, wherein the value ofthe first permission indicator is set at the remote source.
 7. Themethod of claim 1, wherein the at least one permission indicatorcomprises a plurality of permission bits, and the first permissionindicator corresponds to a first of the plurality of permission bits. 8.The method of claim 7, wherein a second of the at least one permissionindicators is associated with a different protected activity, and thesecond permission indicator corresponds to a second of the plurality ofpermission bits.
 9. The method of claim 1, wherein a SWF file comprisesthe sequence of instructions.
 10. A computer program product, encoded ona non-transitory computer-readable medium, operable to cause dataprocessing apparatus to perform operations comprising: receiving, from aserver, a permission indicator associated with an information source andfurther associated with a protected activity; storing, in a persistentstorage device on a mobile device, the permission indicator, wherein thepersistent storage device includes a plurality of segments with eachsegment storing content received from the information source for one ofa plurality of information channels and one of the segments storingcontent and the permission indicator for the information source, withthe content for the information source including a plurality ofinstructions executable by a virtual machine player on the mobiledevice; receiving, through a user interface on the mobile device, arequest to display the content for the information source on a userinterface of the mobile device; retrieving the plurality of instructionsfor execution on a virtual machine player; identifying an instruction ofthe plurality of instructions associated with the protected activity;determining that the protected activity is permitted based, at least inpart, on the permission indicator stored in the persistent storagedevice; and executing the instruction using the virtual machine playerin response to determining that the protected activity is permitted,wherein executing the instruction comprises performing the protectedactivity.
 11. The computer program product of claim 10, the operationsfurther comprising: receiving an updated value for the permissionindicator; and storing, in the persistent storage device, the receivedupdated value for the permission indicator.
 12. The computer programproduct of claim 11, wherein the received updated value for thepermission indicator replaces the permission indicator in the persistentstorage device.
 13. The computer program product of claim 10, theoperations further comprising: receiving, prior to receiving the requestto display the content for the information source, the plurality ofinstructions; storing, in the persistent storage device, the pluralityof instructions; and retrieving the plurality of instructions inresponse to a stimulus from a user of the mobile device.
 14. Thecomputer program product of claim 13, wherein a SWF file comprises theplurality of instructions.
 15. The computer program product of claim 13,wherein the permission indicator and the plurality of instructions arereceived from a remote source in communication with the mobile device.16. The computer program product of claim 15, wherein the value of thepermission indicator is set at the remote source.
 17. The computerprogram product of claim 15, wherein the permission indicator occupiesone of a plurality of permission indicator positions within apermissions data structure, and the permission indicator is assigned tothe one permission indicator position at the remote source.
 18. A systemcomprising: a user interface device; a persistent storage device; andone or more processors operable to interact with the user interfacedevice and the persistent storage device, the one or more processorsfurther operable to: receive a transmission from a remote source, thetransmission comprising a sequence of instructions executable by avirtual machine on the user interface device and a permissions datastructure associated with the sequence of instructions, the permissionsdata structure comprising at least one permission indicator, the atleast one permission indicator associated with at least one protectedactivity on the user interface device, wherein the sequence ofinstructions, when executed by the virtual machine, are adapted topresent content associated with a particular information channel of aplurality of interactive information channels defined in the persistentstorage device in response to a selection of the particular informationchannel through a user interface of the electronic device; store thesequence of instructions and the permissions data structure in aparticular segment of the persistent storage device, wherein thepersistent storage device includes a plurality of segments, with eachsegment corresponding to one of the plurality of information channelsand the particular segment corresponds to the particular informationchannel; retrieve the sequence of instructions and the permissions datastructure from the persistent storage device in response to a stimulusreceived through the user interface device, the stimulus indicating arequest to display the content associated with the particularinformation channel; execute the sequence of instructions using thevirtual machine; determine, using the virtual machine, that a firstprotected activity is prohibited based, at least in part, on the atleast one permission indicator; and block the first protected activitybased on the determination that the first protected activity isprohibited.
 19. The system of claim 18, wherein the one or moreprocessors comprise a client operable to interact with the remote sourcethrough a data communication network, and the remote source is operableto interact with the client as a server.
 20. The system of claim 18,wherein the value of the at least one permission indicator is set at theremote source.
 21. The system of claim 18, wherein the permissions datastructure comprises a plurality of permission bits, and each permissionindicator corresponds to a permission bit.
 22. The system of claim 21,wherein the number of permission bits is greater than the number ofpermission indicators.
 23. The system of claim 18, wherein the at leastone permission indicator comprises a first permission indicator and asecond permission indicator, and wherein the determination that thefirst protected activity is prohibited is based on the first permissionindicator.
 24. The system of claim 23, the one or more processorsfurther operable to determine that a second protected activity ispermitted based on the second permission indicator, wherein executingthe sequence of instructions further comprises performing the secondprotected activity.
 25. The system of claim 18, wherein a SWF filecomprises the sequence of instructions.